The highly anticipated Glamsterdam network upgrade, a significant milestone in Ethereum’s Layer 1 scaling roadmap, has been postponed on the Hoodi testnet. Originally slated for activation on October 26, 2026, with a planned increase in the network’s gas limit to 200 million, the upgrade has encountered a delay. This postponement affects the scheduled epoch and slot, necessitating a revised timeline for its deployment. A separate announcement detailing the exact reasons for the delay and providing updated guidance for node operators and developers is forthcoming.
The Glamsterdam upgrade, which successfully activated on the Sepolia testnet on October 6, 2026, represents a crucial step towards enhancing Ethereum’s throughput and efficiency. Its core innovations include enshrined proposer-builder separation (ePBS), block-level access lists (BALs), and refined gas pricing mechanisms designed to more accurately reflect the costs associated with transaction execution and the ongoing growth of the Ethereum state. While the Hoodi testnet activation has been deferred, the ultimate goal of mainnet deployment remains on the horizon, though its specific activation date has yet to be determined.
The decision to postpone the Hoodi activation was communicated via an update to the original announcement, stating: "The October 26 Hoodi activation has been postponed, including the scheduled gas-limit increase to 200M. The schedule and activation instructions below have been superseded. See Glamsterdam on Hoodi Postponed for details and operator guidance." This proactive communication aims to ensure that all stakeholders are aware of the revised plans and can adjust their preparations accordingly.
Background and Key Innovations of Glamsterdam
The Glamsterdam upgrade is a composite of two distinct but complementary Ethereum Improvement Proposals (EIPs): the Amsterdam execution layer upgrade and the Gloas consensus layer upgrade. This dual approach allows for comprehensive enhancements across the Ethereum network. The primary objectives of Glamsterdam are to bolster Ethereum’s scalability, improve the efficiency of block production, and provide a more robust and adaptable infrastructure for decentralized applications.
Enshrined Proposer-Builder Separation (ePBS)
At the heart of Glamsterdam is the introduction of enshrined proposer-builder separation (ePBS), detailed in EIP-7732. Historically, block proposers on Ethereum have also been responsible for constructing the blocks they propose. ePBS fundamentally alters this dynamic by formally separating the roles of block proposers and block builders.
Under the ePBS model, block builders will compete to create the most profitable execution payloads. Once a builder has constructed an optimal payload, they will submit a commitment to it, which is then included by the block proposer in the canonical chain. The builder subsequently reveals the full execution payload and its associated blob data. A key innovation of ePBS is the protocol’s direct handling of payment from the builder to the proposer. This eliminates the reliance on potentially complex and less secure third-party middleware solutions that have previously facilitated this exchange, thereby increasing trust and transparency in the block production process.
Furthermore, ePBS introduces a separation between consensus validation and execution validation. This division grants validators more time to thoroughly scrutinize execution payloads before attesting to their validity. A dedicated "payload timeliness committee" will be responsible for verifying that builders have revealed their payloads and that corresponding blob data has been made available within the prescribed timeframe. This enhancement is expected to improve network stability and reduce the risk of invalid blocks being proposed. Validator operators and teams involved in maintaining builder infrastructure are strongly advised to familiarize themselves with these new responsibilities and interface changes in preparation for the upgrade.
Block-Level Access Lists (BALs)
Another transformative element of Glamsterdam is the implementation of block-level access lists (BALs), as outlined in EIP-7928. BALs mandate that each block explicitly records the accounts and storage locations that are accessed during the execution of its transactions. Crucially, these lists are generated alongside the post-transaction state changes, providing a comprehensive audit trail.
The introduction of BALs is designed to significantly enhance the efficiency of node operations. By providing a clear record of accessed state, client software can optimize operations such as reading state data from disk and validating transactions. This parallelization capability is expected to lead to faster block processing times and more efficient computation of state roots, ultimately contributing to higher overall network throughput. The combined effect of ePBS and BALs lays a robust foundation for scaling Ethereum’s execution capacity while ensuring that block validation remains a practical and manageable task for node operators.
Gas Pricing and State Growth Adjustments
Glamsterdam also brings significant adjustments to Ethereum’s gas pricing mechanisms, aiming to better align gas costs with actual resource consumption. EIP-8037 introduces an increased and separately metered cost for state creation, a critical component of smart contract development and deployment. Simultaneously, EIP-8038 revises the costs associated with accessing state, ensuring that the economic incentives reflect the resources required to interact with and maintain the blockchain’s state.
Beyond these core EIPs, further modifications will address intrinsic transaction gas costs, calldata gas usage, access list gas accounting, and the overall block gas accounting framework. These repricing efforts are crucial for managing state growth and ensuring the long-term sustainability and scalability of the Ethereum network.
Application developers are strongly encouraged to thoroughly test their smart contracts and gas estimation tools against these new rules. Contracts that rely on fixed gas stipends, hardcoded gas limits, or make assumptions about the amount of remaining gas available during execution may require adjustments. A comprehensive guide, "Glamsterdam Repricing Impact Guide," has been made available to assist developers in identifying potentially affected contracts and conducting necessary testing. This guide includes resources for searching for affected contracts and outlines best practices for adaptation.
Developer and Validator Improvements
In addition to the major scaling and efficiency upgrades, Glamsterdam incorporates several quality-of-life improvements for developers and validators. These include the addition of ETH transfer logs, which can simplify the tracking and auditing of Ether movements, and a slot-number opcode, providing developers with direct access to block slot information within smart contracts. The maximum contract size will also be increased, allowing for more complex and feature-rich decentralized applications. A deterministic factory contract will further streamline contract deployment processes.
For consensus layer operations, Glamsterdam introduces forward-compatible data structures, enhancing the network’s ability to accommodate future upgrades. A critical security enhancement is the exclusion of slashed validators from proposing blocks, ensuring that nodes that have acted maliciously are prevented from participating in network consensus. Furthermore, changes are being implemented to increase the churn rate for validator exits and consolidations, allowing for more dynamic and responsive validator management.
Scheduled EIPs for Glamsterdam
The Glamsterdam upgrade encompasses a carefully curated list of EIPs designed to achieve its objectives. The primary EIP for tracking the upgrade itself is EIP-7773. The following EIPs are scheduled for inclusion:
- EIP-7732: Enshrined Proposer-Builder Separation
- EIP-7928: Block-Level Access Lists
- EIP-8037: State Creation Gas Cost Increase
- EIP-8038: State Access Gas Cost Update
- EIP-XXXX: (Specific EIP for ETH Transfer Logs – exact number to be confirmed)
- EIP-XXXX: (Specific EIP for Slot Number Opcode – exact number to be confirmed)
- EIP-XXXX: (Specific EIP for Increased Maximum Contract Size – exact number to be confirmed)
- EIP-XXXX: (Specific EIP for Deterministic Factory Contract – exact number to be confirmed)
- EIP-XXXX: (Specific EIP for Consensus Layer Forward-Compatible Data Structures – exact number to be confirmed)
- EIP-XXXX: (Specific EIP for Excluding Slashed Validators from Proposing – exact number to be confirmed)
- EIP-XXXX: (Specific EIP for Increased Exit and Consolidation Churn – exact number to be confirmed)
In addition to these core protocol enhancements, EIP-7773 also lists supporting networking and informational EIPs that facilitate the smooth integration and operation of Glamsterdam.
Security Considerations and Bug Bounty Program
The Ethereum Bug Bounty Program remains active for Glamsterdam specifications and the included EIPs. Client implementations become eligible for rewards as soon as their releases are officially designated as supporting the upgrade and are added to the relevant client release tables. Developers and security researchers are encouraged to review the specifications and report any vulnerabilities discovered. Further details regarding reward multipliers and reporting procedures can be found on the official Ethereum Bug Bounty Program website.
Activation Timeline and Process
The agreed-upon deployment schedule, which has been incorporated into the Hoodi network configuration, outlines the activation points for various testnets. While the Hoodi activation has been postponed, the initial successful activation on Sepolia at epoch 353,024, slot 11,296,768, on October 6, 2026, served as a crucial validation step.
The original plan for Hoodi was to activate at epoch 132,352, slot 4,235,264, on October 26, 2026, at 17:42:48 UTC. At this epoch, the gas limit was intended to be raised to 200 million, mirroring the adjustment made on Sepolia via EIP-8261. The mainnet activation date for Glamsterdam is still under consideration and will be announced separately once a consensus is reached among client teams. This announcement specifically pertains to the Hoodi testnet and does not pre-schedule the mainnet upgrade.
Client Releases and Operator Guidance
Compatibility with the Hoodi testnet upgrade requires node operators to update both their execution and consensus layer clients. Hoodi-compatible client releases will be progressively added to dedicated tables as they are confirmed by their respective development teams. It is imperative for operators to consult these tables and ensure they are using a client version whose release notes explicitly confirm support for the scheduled Glamsterdam activation on Hoodi.
- Consensus Layer Hoodi Releases: Node operators running validators must update both their Consensus Layer Beacon Node and Validator Client software. Specific release versions and download links will be provided as they become available.
- Execution Layer Hoodi Releases: Similarly, execution layer clients need to be updated to compatible versions. These releases will also be listed with relevant download information.
- Tooling: The availability of compatible tooling is also critical. For instance, commit-boost, a tool that can assist in optimizing block production, has released a pre-release version (0.12.0-rc1) designated for this upgrade, with download links provided. Further guidance on other builder and validator tooling compatibility for Hoodi will be issued as it is confirmed. Operators utilizing external block-building infrastructure should also consult specific upgrade instructions provided by their service providers.
Frequently Asked Questions (FAQ)
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How do Ethereum network upgrades work?
Ethereum network upgrades are a collaborative effort that requires explicit opt-in from node operators. Client developers coordinate the technical changes, and it is the responsibility of validators and non-staking nodes to update their software to support the new protocol rules. A node that does not upgrade will be unable to participate in the network after the activation of the upgrade. Effective coordination among all stakeholders is paramount for a successful network upgrade. -
As an Ethereum mainnet user or ETH holder, is there anything I need to do?
No immediate action is required for Ethereum mainnet users or ETH holders. This announcement concerns the Hoodi testnet upgrade. A separate communication will be issued regarding the mainnet activation of Glamsterdam. -
As a non-staking Hoodi node operator, what do I need to do?
Before the activation date on Hoodi, ensure that both your execution and consensus layer clients are updated to releases that explicitly support the Glamsterdam upgrade. Refer to the client release tables for confirmed versions. -
As a Hoodi staker, what do I need to do?
Stakers must update their execution and consensus layer clients prior to the Hoodi activation. Crucially, both the beacon node and validator client must be updated. Operators should review their client’s specific upgrade instructions, paying close attention to any new duties related to ePBS, required tooling configurations, and adjustments to the targeted gas limit post-activation. -
As a mainnet node operator or staker, what do I need to do?
No action is required at this time for mainnet participants based on this Hoodi testnet announcement. Information regarding the mainnet activation date and compatible client releases will be communicated separately. -
As an application or tooling developer, what should I do?
Developers should thoroughly review the EIPs scheduled for inclusion in Glamsterdam. It is highly recommended to test applications on the Sepolia and Hoodi testnets following their respective activations. Pay close attention to changes in gas accounting, event logs, opcodes, and client interfaces that might impact your projects. The repricing impact guide should be consulted to identify contracts dependent on fixed gas assumptions and to update gas estimation mechanisms as necessary. -
Why "Glamsterdam"?
Ethereum’s network upgrades are named thematically. Execution layer upgrades often adopt names of cities that have hosted Devcon or Devconnect events. Consensus layer upgrades are named after stars. Glamsterdam is a portmanteau of "Gloas" (a consensus layer upgrade) and "Amsterdam," the host city of Devconnect in 2022.
The postponement of the Hoodi testnet activation underscores the iterative and meticulous process of upgrading Ethereum’s core protocol. By thoroughly testing on testnets like Sepolia and Hoodi, the development community aims to identify and address any potential issues before deploying these significant changes to the mainnet, ensuring the continued security, scalability, and robustness of the Ethereum network.
